Genetic and environmental determinants of bone quality: a cross-sectional analysis of the Hungarian Twin Registry.

There is abundant evidence that bone mineral content is highly heritable, while the heritability of bone quality (i.e. trabecular bone score [TBS] and quantitative ultrasound index [QUI]) is rarely investigated. We aimed to disentangle the role of genetic, shared and unique environmental factors on TBS and QUI among Hungarian twins. Our study includes 82 twin (48 monozygotic, 33 same-sex dizygotic) pairs from the Hungarian Twin Registry. TBS was determined by DXA, QUI by calcaneal bone ultrasound. To estimate the genetic and environmental effects, we utilized ACE-variance decomposition. For the unadjusted model of TBS, an AE model provided the best fit with > 80% additive genetic heritability. Adjustment for age, sex, BMI and smoking status improved model fit with 48.0% of total variance explained by independent variables. Furthermore, there was a strong dominant genetic effect (73.7%). In contrast, unadjusted and adjusted models for QUI showed an AE structure. Adjustments improved model fit and 25.7% of the total variance was explained by independent variables. Altogether 70-90% of the variance in QUI was related to additive genetic influences. We found a strong genetic heritability of bone quality in unadjusted models. Half of the variance of TBS was explained by age, sex and BMI. Furthermore, the adjusted model suggested that the genetic component of TBS could be dominant or an epistasis could be present. In contrast, independent variables explained only a quarter of the variance of QUI and the additive heritability explained more than half of all the variance.

Comparison of the femoral neck bone density, quantitative ultrasound and bone density of the heel between dominant and non-dominant side.

Our study was initiated to evaluate whether there are differences between the two sides, depending on hand dominance, in densitometry values and quantitative ultrasound parameters (QUS) of the lower limb. One hundred and six women and 44 men were involved. The hand dominance was determined by interview. The bone mineral density (BMD) of the left and the right femoral necks and the calcanei were measured by dual-energy X-ray absorptiometry (DXA). The QUS examination consisted of measuring the attenuation (BUA), the speed of the ultrasound (SOS) and quantitative ultrasound index (QUI) transversing the left and right calcanei. The density of the neck of femur of the non-dominant side did not differ from that of the dominant side. On the other hand, BMD, BUA and the QUI of the calcaneus were higher on the non-dominant side in both genders (p<0.05 for each parameter). No similar differences were seen for the SOS values. Our study has confirmed the side-to-side differences of the calcaneus in both genders, lower values were found on the dominant side. No similar differences were seen on the femur. The AUC values seemed to be higher on the dominant side, however, these differences were not strictly significant. In the case of peripheral site (heel) measurements, the practical significance of our observations is that they raise the possibility of performing peripheral DXA and QUS examinations of the calcaneus on the dominant side of the patient according to handedness.

[Effect of cigarette smoking on bone quality parameters in women]. / A dohányzás hatása a nok csontjának minoségi jellemzoire.

INTRODUCTION: Smoking is a risk factor for osteoporosis. In a previous study, the authors showed lower bone density among smokers in a group of postmenopausal women. AIMS: After this finding, the primary goal of current research was to investigate how smoking could influence bone quality. METHODS: Forty-five (age range: 25-72 ys) smoker women were compared with 45 nonsmoker women adjusted for age and anthropometric parameters. Quantitative ultrasound method was used to determine the speed of ultrasound and the ultrasound attenuation transmitting the left heel (Achilles In Sight, GE Lunar). Dual photon absorptiometry method was applied to investigate the bone mineral density of lumbar spine and left femoral neck (Prodigy, GE Lunar) and single photon absorptiometry was used to determine the bone mineral content of radius at the non dominant side (NK-364, Gamma). RESULTS: No difference was found between smokers and non-smokers among the premenopausal group, however, postmenopausal smoker women had slightly lower speed of ultrasound and ultrasound attenuation values than non-smoker women. Postmenopausal smoker women suffering from bone fracture had significantly lower speed of ultrasound than postmenopausal non-smoker women (1508.9 vs. 1525.3 m/s, respectively), despite their bone density did not differ from each other. CONCLUSION: These data augment the knowledge about the injurious effect of smoking. The increased risk for bone fracture among smokers could be explained not only with the decrease of bone mass, which was previously described, but also with a decreased bone elasticity.

The effect of intranasal salmon calcitonin therapy on bone mineral density in idiopathic male osteoporosis without vertebral fractures--an open label study.

The aim of this study was to examine the effect of intranasal salmon calcitonin therapy on bone mineral density (BMD) in idiopathic male osteoporosis without vertebral fractures. We conducted a randomized, open label, controlled trial in 71 male patients (mean age 59 +/- 6 years) suffering from idiopathic osteoporosis (femoral neck T-score < -2.5) without vertebral deformity. Patients in the control group (n = 31) received 400 IU Vitamin D + 1000 mg elemental calcium daily while the treatment group (n = 40) received 400 IU Vitamin D, 1000 mg elemental calcium plus 200 IU calcitonin nasal spray daily during alternate months. The study period was 18 months. Compared to controls, nasal calcitonin was associated with significant increases in bone mineral density at the lumbar spine (+3.5 +/- (-4.3%) vs. +0.83 +/- 6.4%, P = 0.04) and the femoral neck (+3.2 +/- 3.9% vs. +0.68 +/- 5.7%, P = 0.004). No significant difference was observed at the radius between the treatment groups (+1.4 +/- 8.8% vs. +1.4 +/- 10.9%, P = 0.98). Treatment was well tolerated with no premature discontinuations or significant side effects compared to the control group. We conclude that 200 IU salmon calcitonin nasal spray used daily, intermittently proved to be an effective and safe therapy in male idiopathic osteoporosis.

[Effects of body mass index on bone mineral density in men]. / Testtömeg hatása a férfiak csonttömegére.

INTRODUCTION: A strong positive association between body mass index and bone mineral density is well defined in postmenopausal osteoporosis, but not in men. AIMS: The primary goal of the current research was to investigate this association in case of men. METHODS: According to WHO criteria (T-score below -1.0 at all measure site) seventy-two (mean age 55.7 +/- 0.99, range 38-78 yr normal density) healthy male with normal density were recruited. Exclusion criteria were the absence of any risk factors or signs of metabolic disease. Bone mineral measurements at the lumbar spine (L2-4) and femoral neck were performed by the dual-energy X-ray absorptiometry (DEXA, Lunar DPX-L, USA), bone mineral content of the non-dominant radius was measured with single photon absorptiometry (SPA, NK-364, Hungary). Participants were divided into three groups according to body mass index normal weight (18.5-24.9 kg/m2), moderate overweight (25-29.9 kg/m2) and obese subjects (> 30 kg/m2). RESULTS: Femur neck density was significantly lower in the normal weight than in the overweight counterparts (0.969 +/- 0.03 vs 1.062 +/- 0.02 p = 0.01). There was a strong positive association between BMI and femur neck BMD (r = 0.412 p < 0.001). Body mass was an independent predictor of femur neck bone mineral density (regression coefficients 0.382, p = 0.001). There was not correlation at the lumbar spine and the radius sites. CONCLUSION: Bone density at femur neck sites is lower in the normal weight men than in obese subjects, therefore the risk factors for proximal femur osteoporosis are higher in these cases. Prevention strategy is needed for men in the lowest quintile of body mass to prevent further decrease in BMD and reduce the risk of hip fracture.

Calcaneous quantitative ultrasound measurements predicts vertebral fractures in idiopathic male osteoporosis.

OBJECTIVES: The aim of this study was to identify the differences in ultrasound bone variables (QUS) and to test the ability to discriminate male patients with and without vertebral fractures. METHODS: We therefore measured broadband ultrasound attenuation (BUA) and speed of sound (SOS) matched for bone mineral density (BMD) and vertebral deformity in idiopathic male osteoporosis. RESULTS: One hundred and seventeen men (age 56.6 range 27-78) were divided into three groups (osteoporosis n=25, osteopenia n=58 and age-matched control n=34) according to BMD T-score by WHO criteria. We found 66 patients (56%) with at least one vertebral deformity during the study. BMD and BUA did not differ, while SOS was lower in osteoporosis (p<0.001) and control group (p<0.001) between the patients with and without vertebral compression. Strong positive correlation was demonstrated between BUA and BMD (lumbar spine r=0.44, p<0.001, femoral neck r=0.56, p<0.001, radius r=0.40, p<0.001), while similar association between SOS and BMD values was not shown. There was no relationship between the BUA and vertebral fracture risk (Odds ratio: 1.14 95% CI: 0.80-1.61). However, the relative risk of vertebral fracture by SOS was 1.56 (95% CI: 1.08-2.62). Adjusting for age and BMI the risk of vertebral fracture did not change (odds ratio for SOS 1.50 95% CI: 1.02-2.22). After adjustment for BMD SOS was still associated with fracture risk at all measured sites (odds ratio: 1.43, 95% CI: 1.02-2.22; 1.41, 95% CI: 1.02-2.17 and 1.32, 95% CI: 1.02-2.0). CONCLUSION: Our results suggest that BUA values are more closely related to density and structure while SOS values are able to predict fractures.

Increased bone fracture prevalence in postmenopausal women suffering from pollen-allergy.

INTRODUCTION: Our aim was to investigate whether pollen-allergy can affect bone mass and fractures in postmenopausal women. METHODS: A total of 125 postmenopausal pollen-allergic women (mean age: 61.26 yr) were split into four groups: (1) treated with neither H1 histamine receptor (H1R) antagonist nor inhaled corticosteroid (n=43); (2) treated only with H1R antagonist (n=53); (3) treated with both H1R antagonist and inhaled corticosteroid (n=17); (4) treated with only inhaled corticosteroid (n=12). Treatment, in the appropriate groups, had occurred for at least 5 years, seasonally. One-hundred non-allergic postmenopausal subjects matched for age, body mass index (BMI), and age at menopause served as controls. RESULTS: Overweight and obesity (25 kg/m(2) < or =BMI) were common among the allergic women (76%). Allergic patients without treatment had a slightly lower bone density than their non-allergic counterparts. The rate (34.9%) of prevalent low-energy fractures (distal forearm, hip, and clinical vertebral fractures) in untreated allergic patients was almost triple that observed in non-allergic women (13%, chi(2) p=0.003). Bone fracture occurred more often in H1R-only treated patients (30.19%) than in controls (chi(2) p=0.01); however, clinical vertebral or hip fractures developed neither in those treated only with H1R antagonist nor in those who received both H1R antagonist and inhaled corticosteroid. Bone fractures were more frequent among patients with inhaled steroid treatment than among patients with a combined treatment of inhaled steroid and antihistamine (50 versus 29.4%). BMI predicted prevalent fractures at 1.278 (95% CI: 1.047-1.559, p=0.016) for a 1 kg/m(2) increase among untreated allergic patients. CONCLUSION: In conclusion, we found a high prevalence of low-energy fractures among pollen-allergic postmenopausal women which was associated with obesity. It is possible that the H1R antagonists compensate for both the negative effect of pollen-allergy and the adverse effect of inhaled corticosteroid treatment on bone fracture risk.